Beam-steering devices and methods for LIDAR applications

Abstract

A LIDAR apparatus for scanning a scene is provided that includes a transmitter stage, a receiver stage, a beam-steering engine configured to steer the light beam received from the transmitter stage in different directions to scan at least a portion of the scene. The beam-steering engine is responsive to steering commands to produce corresponding deflections of the light beam.

The invention claimed is: 
     
       1. A LIDAR apparatus comprising:
 a. a transmitter including a light source configured to emit a pulsed light beam, 
 b. a non-mechanical beam-steering stage configured to receive the light beam and deflect the light beam at a deflection angle selected among a plurality of discrete deflection angles, into a Field of View (FOV) defining a set of tiles which can be selectively illuminated by the light beam, and which are associated with respective ones of the deflection angles, 
 c. a receiver being configured to collect pulsed light returns emitted from the light source and back scattered from an object in a scene to produce electrical output signals representative of acquisitions of light pulses, 
 d. a controller coupled to the receiver, the controller configured to determine an estimated distance to the object based on processing the output signals, wherein the processing of the output signals comprises sampling the output signals to obtain sampled acquisitions of light pulses, the controller configured to:
 i. obtain distance measurements from accumulation of a number of sampled acquisitions of light pulses, 
 ii. output a depth map including the distance measurements as a succession of LIDAR data frames, 
 iii. implement an accumulation scheme including determining a total number of accumulations available for a LIDAR data frame and dynamically performing a distribution of the total number of accumulations on a tile-by-tile basis of the FoV, including processing the output signals on the basis of the distribution to generate the depth map. 
 
 
     
     
       2. The LIDAR apparatus as defined in  claim 1 , wherein the beam-steering stage is configured to steer the light beam stepwise. 
     
     
       3. The LIDAR apparatus as defined in  claim 1 , wherein the beam-steering stage includes an optical element switchable between a first operational mode and a second operational mode without mechanical movement of the optical element, in the first operational mode the beam-steering stage is configured to output the light beam passing through the beam-steering stage, along a first propagation direction, in the second operational mode the beam-steering stage is configured to output the light beam along a second propagation direction. 
     
     
       4. The LIDAR apparatus as defined in  claim 1 , wherein the accumulation scheme is such that the number of accumulations to obtain a distance measurement varies between two adjacent tiles. 
     
     
       5. The LIDAR apparatus as defined in  claim 4 , wherein the accumulation scheme varies the number of accumulations to obtain a distance measurement horizontally in the FoV. 
     
     
       6. The LIDAR apparatus as defined in  claim 4 , wherein the accumulation scheme varies the number of accumulations to obtain a distance measurement vertically in the FoV. 
     
     
       7. A LIDAR apparatus as defined in  claim 1 , wherein the controller is responsive to a control signal to vary the accumulation scheme. 
     
     
       8. The LIDAR apparatus as defined in  claim 1 , wherein the controller is responsive to a control signal to increase the number of accumulations associated with a first tile of the FOV. 
     
     
       9. The LIDAR apparatus as defined in  claim 8 , wherein the controller is responsive to a control signal to decrease the number of accumulations associated with the first tile of the FOV. 
     
     
       10. The LIDAR apparatus as defined in  claim 9 , wherein the controller is responsive to the control signal to decrease the number of accumulations associated with the first tile of the FOV and increase the number of accumulations associated with a second tile of the FOV.